CN113541456A

CN113541456A - Full-voltage high-frequency direct conversion isolated safety power supply

Info

Publication number: CN113541456A
Application number: CN202111088620.1A
Authority: CN
Inventors: 刘震; 李名银
Original assignee: Huabang Chuangke Huizhou Intelligent Technology Co ltd
Current assignee: Huabang Chuangke Huizhou Intelligent Technology Co ltd
Priority date: 2021-09-16
Filing date: 2021-09-16
Publication date: 2021-10-22
Anticipated expiration: 2041-09-16
Also published as: CN113541456B

Abstract

The invention relates to a full-voltage high-frequency direct conversion isolated safety power supply, which comprises: the high-frequency transformation conversion device comprises a front-stage IGBT switch group, a high-frequency transformer and a rear-stage IGBT switch group which are sequentially connected, wherein a direct current or alternating current power supply is input to the input end of the front-stage IGBT switch group, and the direct current or alternating current power supply converted by the high-frequency transformer is output by the rear-stage IGBT switch group; the driving device comprises a signal driving module and a driving control circuit, wherein the driving control end of the signal driving module is electrically connected with the front stage IGBT switch group, the high-frequency transformer and the rear stage IGBT switch group, and the signal driving module is electrically connected with the driving control circuit; the synchronous signal generating device comprises a synchronous fundamental wave circuit, a synchronous carrier wave circuit and a synchronous restoring circuit. The power frequency transformer is used for solving the technical problems of large volume, high cost, low conversion efficiency, large loss and large heat productivity of the existing power frequency transformer.

Description

Full-voltage high-frequency direct conversion isolated safety power supply

Technical Field

The invention relates to the field of safety power supplies, in particular to a full-voltage high-frequency direct conversion isolation type safety power supply.

Background

For the safety of the consumers, the input power supply is generally isolated from the mains supply by a 1:1 power frequency transformer, so that the consumers cannot get an electric shock any matter which line of the line is touched, and the isolated power supply is not connected with the ground.

As is known, if the 220V ac power is to be subjected to the safety processing, an isolation transformer is required, the larger the capacity is, the larger the volume capacity of the isolation transformer is, and if the DC power voltage is to be subjected to 1:1 isolation output, a DC-DC isolation transformation device is required, so that the triangular wave voltage and the square wave voltage with unequal amplitudes cannot be converted by the transformer, even if the conversion is possible, the distortion may occur, and the square wave voltage is no longer the standard square wave voltage, and the triangular wave voltage becomes not the triangular wave voltage. And the existing circuit for carrying out safe electrical isolation is quite complex and has higher cost.

In addition, in the prior art, the isolation of alternating current is realized by simply adopting an alternating current power frequency transformer, a high frequency transformer is mostly adopted for direct current voltage or pulse direct current voltage, an inversion method is mostly adopted for alternating current square wave or triangular wave voltage, and phase difference is generated regardless of power frequency or high frequency.

Disclosure of Invention

The application provides a full-voltage high-frequency direct conversion isolated safety power supply, which is used for solving the technical problems of large volume, high cost, low conversion efficiency, large loss and large heat productivity of the existing power frequency transformer.

The present application provides in a first aspect a full voltage high frequency direct conversion isolated safety power supply, including: a high-frequency transformation conversion device, a driving device and a synchronous signal generating device,

the high-frequency transformation conversion device comprises a front-stage IGBT switch group, a high-frequency transformer and a rear-stage IGBT switch group which are sequentially connected, wherein the input end of the front-stage IGBT switch group is used for inputting a direct current or alternating current power supply, and the rear-stage IGBT switch group is used for outputting the direct current or alternating current power supply converted by the high-frequency transformer;

the driving device comprises a signal driving module and a driving control circuit, wherein the driving control end of the signal driving module is respectively and electrically connected with the front stage IGBT switch group, the high-frequency transformer and the rear stage IGBT switch group, and the signal driving module is electrically connected with the driving control circuit;

the synchronous signal generating device comprises a synchronous fundamental wave circuit, a synchronous carrier circuit and a synchronous reduction circuit, wherein the input end of the synchronous fundamental wave circuit is used for inputting a direct current or alternating current power supply, the output end of the synchronous fundamental wave circuit is respectively connected with the signal driving module and the synchronous carrier circuit electrically, the synchronous carrier circuit inputs the converted carrier signal to the signal driving module according to the control signal of the driving control circuit and the square wave signal of the synchronous fundamental wave circuit, and the synchronous reduction circuit inputs the reduced signal to the signal driving module according to the control signal of the driving control circuit.

Optionally, the driving control circuit includes a phase-shifting driving module and a PWM control module, the phase-shifting driving module is electrically connected to the synchronous fundamental wave circuit, the synchronous carrier circuit and the synchronous restoring circuit, respectively, and the PWM control module is electrically connected to the phase-shifting driving module.

Optionally, the safety power supply further includes a front-stage LC filter and a rear-stage LC filter, the front-stage LC filter is connected to the input end of the front-stage IGBT switch group, and the rear-stage LC filter is connected to the output end of the rear-stage IGBT switch group.

Optionally, the synchronous fundamental wave circuit includes an under-voltage unit, a voltage dividing unit, an input signal modulation unit and a synchronous square wave modulation unit, the under-voltage unit is used for accessing a direct current or alternating current power supply, a voltage at an output end of the under-voltage unit is input to the input signal modulation unit after being divided by the voltage dividing unit, the input signal modulation unit outputs high and low level signals to the synchronous square wave modulation unit, and the synchronous square wave modulation unit outputs square wave signals according to the high and low level signals output by the input signal modulation unit.

Optionally, the input signal modulation unit includes a positive half-cycle modulator and a negative half-cycle modulator, an input end of the positive half-cycle modulator is electrically connected to one end of the voltage division unit and one end of the power input end, an output end of the positive half-cycle modulator is electrically connected to one input end of the synchronous square wave modulation unit, an input end of the negative half-cycle modulator is electrically connected to the other end of the voltage division unit and the other end of the power input end, and an output end of the negative half-cycle modulator is electrically connected to the other input end of the synchronous square wave modulation unit.

Optionally, the synchronous square wave modulation unit includes a positive half-cycle optocoupler switch module, a negative half-cycle optocoupler switch module, and an interlocking branch, the positive half-cycle optocoupler switch module outputs a positive half-cycle square wave signal according to a level signal of the input signal modulation unit, the negative half-cycle optocoupler switch module outputs a negative half-cycle square wave signal according to the level signal of the input signal modulation unit, and the interlocking branch is electrically connected with output ends of the positive half-cycle optocoupler switch module and the negative half-cycle optocoupler switch module, respectively.

Optionally, the synchronous carrier circuit includes a preceding positive half cycle carrier modulation unit and a preceding negative half cycle carrier modulation unit, the preceding positive half cycle carrier modulation unit inputs the converted positive half cycle carrier signal to the signal driving module according to the control signal of the driving control circuit and the square wave signal of the synchronous fundamental wave circuit, and the preceding negative half cycle carrier modulation unit inputs the converted positive half cycle carrier signal to the signal driving module according to the control signal of the driving control circuit and the square wave signal of the synchronous fundamental wave circuit.

Optionally, the synchronous reduction circuit includes a positive half-cycle driving branch and a negative half-cycle driving branch, an input end of the positive half-cycle driving branch is electrically connected to two phase-shift signal output ends of the phase-shift driving module, an output end of the positive half-cycle driving branch inputs a reduced positive signal to the signal driving module, an input end of the negative half-cycle driving branch is electrically connected to the other two phase-shift signal output ends of the phase-shift driving module, and an output end of the negative half-cycle driving branch inputs a reduced negative signal to the signal driving module.

Optionally, the safety power supply further comprises an input relay and an output relay, wherein the input relay is used for being connected between a power input end and the front stage IGBT switch group, and the output relay is used for being connected between a power output end and the rear stage IGBT switch group.

Optionally, the safety power supply further includes an input voltage detector, an output voltage detector, a temperature detector and a wireless transmission module, an input end of the input voltage detector is electrically connected to an output end of the input relay, an input end of the output voltage detector is electrically connected to an input end of the output relay, a detection end of the temperature detector is electrically connected to the front stage IGBT switch group, the high frequency transformer and the rear stage IGBT switch group, respectively, and the driving control circuit is electrically connected to output ends of the input voltage detector, the output voltage detector and the temperature detector and the wireless transmission module, respectively.

According to the technical scheme, the method has the following advantages:

1. the full-voltage high-frequency direct conversion isolated safety power supply provided in the application can solve the problems of large volume, high cost, low conversion efficiency, large loss and large heat productivity of the existing power frequency transformer by arranging the high-frequency transformation conversion device, the driving device and the synchronous signal generating device, can directly carry out high-voltage high-frequency conversion, and achieves the effects of high efficiency, small loss and small heat productivity.

2. The high-frequency conversion mode of the safety power supply can be used for modulating and restoring any voltage in a synchronous mode, and the cost and the volume of the transformer can be effectively reduced.

3. According to the invention, by arranging the front stage IGBT switch group, the high frequency transformer and the rear stage IGBT switch group, the input power supply voltage of the bidirectional switch formed by the IGBTs can be disassembled into four quadrants, and finally restored into the initial input power supply voltage through the high frequency transformer.

4. The invention makes the safety power supply work in AC, DC state and asymmetric differential voltage by setting the front stage IGBT switch group and the back stage IGBT switch group, further solves the problems of large volume, high loss and large heat of the power frequency transformer, and can realize the purpose of direct equivalent isolation.

5. The invention also can realize the waveform correction by arranging the front-stage LC filter and the rear-stage LC filter, and the drive control circuit can correct the waveform of the output voltage in real time along with the waveform of the power grid when the sine wave is irregular.

Drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings needed to be used in the description of the embodiments are briefly introduced below, and it is obvious that the drawings in the following description are only some embodiments of the present application, and it is obvious for those skilled in the art to obtain other drawings based on these drawings without inventive exercise.

Fig. 1 is a schematic block diagram of a full-voltage high-frequency direct-conversion isolated safety power supply according to an embodiment of the present invention;

fig. 2 is a circuit diagram of the high frequency transformation switching device shown in fig. 1;

FIG. 3 is a circuit diagram of the preceding stage IGBT switch set shown in FIG. 2;

FIG. 4 is a diagram of the switch conducting states of the preceding stage IGBT switch set shown in FIG. 3, wherein the conducting states are four different states when the power supply voltage input is positive half cycle;

FIG. 5 is a waveform diagram of the power supply voltage of FIG. 4 modulated from 1 quadrant to 2 quadrants;

fig. 6 is a circuit diagram of a preceding stage IGBT switch group of another embodiment shown in fig. 2;

fig. 7 is a diagram of the switch on states of the preceding IGBT switch group shown in fig. 6, wherein the on states are four different states when the power supply voltage input is negative half cycle;

FIG. 8 is a waveform diagram of the power supply voltage of FIG. 7 modulated from 2 quadrants to 4 quadrants;

fig. 9 is a circuit diagram of the rear stage IGBT switch group shown in fig. 2;

fig. 10 is a diagram of the switch conducting states of the rear stage IGBT switch group shown in fig. 9, wherein the conducting states are diagrams of four different states of the high frequency transformer secondary pulse voltage signal;

FIG. 11 is a waveform diagram illustrating the output of the high frequency transformer shown in FIG. 10 reverting from 2-quadrant to 1-quadrant;

FIG. 12 is a diagram of the switch conduction states of the rear stage IGBT switch bank shown in FIG. 9, wherein the conduction states are a diagram of four other different states of the high frequency transformer secondary pulsed voltage signal;

FIG. 13 is a waveform diagram showing the output of the high frequency transformer shown in FIG. 12 reverting from 4-quadrant to 2-quadrant;

fig. 14 shows the sine wave voltage obtained after the output voltage passes through the low-channel LC filter.

Fig. 15 is a circuit diagram of the synchronous fundamental circuit shown in fig. 1;

fig. 16 is a waveform diagram in which an alternating voltage signal (a), a square wave voltage signal (b), and a triangular wave voltage signal (c) are modulated into a square wave signal by a synchronous fundamental wave circuit;

FIG. 17 is a circuit diagram of a front-stage positive half-cycle carrier modulation unit according to the embodiment shown in FIG. 1;

FIG. 18 is a circuit diagram of a front-stage positive half-cycle carrier modulation unit according to another embodiment shown in FIG. 1;

FIG. 19 is a circuit diagram of a preceding-stage negative half-cycle carrier modulation unit according to the embodiment shown in FIG. 1;

FIG. 20 is a circuit diagram of a preceding-stage negative half-cycle carrier modulation unit according to another embodiment shown in FIG. 1;

FIG. 21 is a circuit diagram of a phase shift driver module of the drive control circuit shown in FIG. 1;

FIG. 22 is a waveform diagram of the phase shifting driver module shown in FIG. 21;

FIG. 23 is a circuit diagram of the synchronous restoration circuit shown in FIG. 1;

FIG. 24 is a waveform diagram of the output of the synchronous restoration circuit shown in FIG. 1;

fig. 25 is a circuit diagram of a PWM control module of the drive control circuit of the first part;

fig. 26 is a circuit diagram of a PWM control module of the drive control circuit of the second part;

fig. 27 is a circuit diagram of a PWM control module of the drive control circuit of the third section.

Detailed Description

The embodiment of the application discloses and provides a full-voltage high-frequency direct conversion isolated safety power supply, which is used for solving the technical problems of large volume, high cost, low conversion efficiency, large loss and large heat productivity of the existing power frequency transformer.

The invention relates to a power supply device capable of isolating and restoring various voltage sources, which can be applied to electric places needing isolation, such as an alternating current-alternating current isolation power supply, a direct current-direct current isolation power supply and a square wave-square wave isolation power supply. The isolated type safety power supply is particularly suitable for being used as an isolated type safety power supply of a low-voltage distribution system, and overcomes the defects of large volume, heavy weight, high manufacturing cost and the like of a power frequency transformer. The IGBT high-frequency switch type treatment is adopted, so that the volume of the transformer is reduced to a few tenths of that of a power frequency transformer, the structure is simple, and the running time is long. The power frequency noise-free power supply has the advantages of low manufacturing cost and the like, can be used in vast places needing isolation of power supplies, and has LC filtering functions for filtering the interference of harmonic junction power grids of equipment after front input and rear output.

Based on the existing technical problem, it is a very good choice to adopt a high-frequency synchronous reduction mode to solve the problem that the original mode is replaced by an isolated safety power supply with various voltages such as alternating current, direct current pulse, square wave, triangular wave and the like. The alternating voltage or the direct voltage is divided into high-frequency voltage signals by using a high-frequency carrier mode, and the input power voltage is synchronously restored by using a synchronous modulation restoration mode.

In one embodiment, referring to fig. 1, a full-voltage high-frequency direct-conversion isolated safety power supply includes: the high-frequency voltage transformation device is used for realizing the conversion of high-frequency voltage; the driving device is used for driving the whole safety power supply to work; the synchronous signal generating device is used for realizing the conversion of synchronous fundamental wave, square wave and carrier wave signals and the conversion of restored signals.

Referring to fig. 1 and 2, the high-frequency transformation and conversion apparatus includes a front IGBT switch group 110, a high-frequency transformer 120, and a rear IGBT switch group 130, which are connected in sequence, wherein an input end of the front IGBT switch group is used for inputting a dc or ac power, and the rear IGBT switch group is used for outputting a dc or ac power transformed by the high-frequency transformer. It should be noted that the preceding stage IGBT switch group 110 is used as a switch to drive the primary side of the high-frequency transformer to work; the high-frequency transformer 120 is used for realizing the conversion of high-frequency voltage; the rear stage IGBT switch group 130 is configured to output the converted high frequency voltage.

Referring to fig. 1 and 2, the safety power supply further includes a front-stage LC filter 410 and a rear-stage LC filter 420, the front-stage LC filter is connected to the input end of the front-stage IGBT switch group, and the rear-stage LC filter is connected to the output end of the rear-stage IGBT switch group. It should be noted that the pre-stage LC filter 410 is used for filtering an input power supply voltage; the post-stage LC filter 420 is used to filter the output voltage.

Referring to fig. 1, the synchronous signal generating device includes a synchronous fundamental wave circuit 310, a synchronous carrier circuit 320, and a synchronous restoring circuit 330, an input end of the synchronous fundamental wave circuit is used for inputting a dc or ac power, an output end of the synchronous fundamental wave circuit is respectively electrically connected to the signal driving module and the synchronous carrier circuit, the synchronous carrier circuit inputs a converted carrier signal to the signal driving module according to a control signal of the driving control circuit and a square wave signal of the synchronous fundamental wave circuit, and the synchronous restoring circuit inputs a restored signal to the signal driving module according to the control signal of the driving control circuit. The synchronous fundamental wave circuit 310 is configured to convert an input power voltage into a synchronous square wave signal, and input the synchronous square wave signal into a corresponding front-stage IGBT switch group through the signal driving module 210, the synchronous carrier circuit 320 converts the square wave signal into a carrier signal according to the square wave signal of the synchronous fundamental wave circuit 310 and the PWM signal of the driving control circuit 220, and inputs the carrier signal into the corresponding front-stage IGBT switch group, and the synchronous restoring circuit 330 inputs a corresponding restored positive and negative signal into a corresponding rear-stage IGBT switch group through the signal driving module 210 according to the PWM signal of the driving control circuit 220.

Referring to fig. 1, the driving apparatus includes a signal driving module 210 and a driving control circuit 220, a driving control end of the signal driving module is electrically connected to the front stage IGBT switch set, the high frequency transformer and the rear stage IGBT switch set, respectively, and the signal driving module is electrically connected to the driving control circuit. It should be noted that the signal driving module 210 is configured to directly transmit the square wave signal of the synchronous fundamental wave circuit 310 and the carrier signal of the synchronous carrier circuit 320 to the switch of the corresponding front-stage IGBT switch group, and also directly transmit the reduction signal of the synchronous reduction circuit 330 to the switch of the corresponding rear-stage IGBT switch group; the driving control circuit 220 is used for driving the operation of each component in the safety power supply.

In this embodiment, the signal driving module 210 is a conventional technology, and the specific configuration may refer to how the conventional driving module implements corresponding transmission of signals.

Referring to fig. 1, the driving control circuit 220 includes a phase-shifting driving module 221 and a PWM control module 222, the phase-shifting driving module is electrically connected to the synchronous fundamental wave circuit, the synchronous carrier circuit and the synchronous restoring circuit, respectively, and the PWM control module is electrically connected to the phase-shifting driving module. It should be noted that the phase shift driving module 221 is configured to control the operation of the synchronous carrier circuit; the PWM control module 222 is used to control the operation of the entire safety power supply.

Referring to fig. 1, the safety power supply further includes an input voltage detector 510, an output voltage detector 520, a temperature detector 530, and a wireless transmission module 540, an input end of the input voltage detector is electrically connected to an output end of the input relay, an input end of the output voltage detector is electrically connected to an input end of the output relay, a detection end of the temperature detector is electrically connected to the front stage IGBT switch group, the high frequency transformer, and the rear stage IGBT switch group, respectively, and the driving control circuit is electrically connected to the input voltage detector, the output voltage detector, an output end of the temperature detector, and the wireless transmission module, respectively. It should be noted that the input voltage detector 510 is configured to detect an input voltage and transmit the input voltage to the PWM control module 222 in real time; the output voltage detector 520 is used for detecting the output voltage; the temperature detector 530 is used for sensing the temperatures of the front stage IGBT switch group, the high frequency transformer and the rear stage IGBT switch group; the wireless transmission module 540 is used for connecting the PMW control module, and transmitting relevant data to an external monitoring device, or receiving a control signal from an external wireless device. In this embodiment, the wireless transmission module 540 is a DTU module, and of course, other modules capable of realizing wireless transmission may also be selected according to actual requirements.

Referring to fig. 1, the safety power supply further includes an input relay 610 and an output relay 620, the input relay is configured to be connected between the power input end and the front stage IGBT switch group, and the output relay is configured to be connected between the power output end and the rear stage IGBT switch group. It should be noted that the input relay 610 is used as a master switch of the power output terminal; the output relay 620 is used as a master switch of the output end of the safety power supply.

Referring to fig. 3, the AC/DC power is filtered by the inductor L1 and the capacitor C1 of the LC filter of the preceding stage and then sent to the IGBT switch group of the preceding stage, and since the IGBT switch group is a bidirectional electronic switch formed by coupling the common emitter and the power input is connected to the collector terminal of the IGBT, the current cannot enter the primary side of the transformer T1 regardless of the AC or DC current when the IGBT switch group does not have a driving signal.

Hereinafter, AC input power is taken as an example. When the power input is AC power, the synchronous fundamental wave circuit detects the positive and negative half-wave of the input power voltage and disassembles the positive and negative half-wave into square wave synchronous signals. The frequency phase of which is identical to the input power.

When the input voltage is positive half cycle, the synchronous fundamental wave circuit sends synchronous fundamental waves into the switches K2, K4, K6 and K8 of the IGBT switch group. At the moment, switches of K2, K4, K6 and K8 of the IGBT switch group are conducted, the voltage is positive, negative and positive, the conduction of the switches of K2, K4, K6 and K8 of the IGBT switch group is equivalent to a lead, and the switches of K1, K3, K5 and K7 of the IGBT switch group send carrier signals modulated by a phase-shift driving module of a driving control circuit, namely the carrier signals output by a synchronous carrier circuit, so that a full-bridge phase-shift soft switch circuit is formed.

Referring to fig. 4(a), when the switches K1 and K7 of the IGBT switch group are turned on, the primary voltage of the high-frequency transformer is positive, negative, and up. Referring to fig. 4(b), when K1 is turned off and K5 is turned on, the circuit enters a zero-voltage switching state (ZVS state) to achieve a soft switching effect. Referring to fig. 4(c), when the power voltage is split from quadrant 1 to quadrant 2, K7 is turned off, K3 is turned on, and the transformer changes from the original upper positive, lower negative to lower positive, upper negative. Referring to fig. 4(d), when K5 is turned off and K1 is turned on, the ZVS state is entered again.

Referring to fig. 5, the positive half cycle voltage of the input power is modulated from 1 quadrant to 2 quadrants of high frequency ac pulse voltage, which is sent to the primary of the high frequency transformer, and the voltage waveform on the primary winding of the high frequency transformer is obtained.

Referring to fig. 6, when the power voltage input is negative half cycle, the sync signal is inverted and the fundamental wave driving sync square wave signal is sent to the K1, K3, K5, K7 switches of the IGBT switch group. At this time, the switches K1, K3, K5 and K7 of the IGBT switch group are equivalent to wires, and the switches K2, K4, K6 and K8 of the IGBT switch group are used for full-bridge phase-shift PWM adjustment, and at this time, the circuit voltage is negative and positive.

Referring to fig. 7(a), when the switches K2, K8 are turned on, the transformer is turned on, and the direction of the current is shown.

Referring to fig. 7(b), when the switch K8 is turned off and the switches K2 and K4 are turned on, the high frequency transformer enters ZVS state.

Referring to fig. 7(c), when the switch K2 is turned off and the switches K4 and K6 are turned on, the voltage direction of the high frequency transformer is positive, negative, and up.

Referring to fig. 7(d), when the switch K4 is turned off and the switches K6 and K8 are turned on, the high frequency transformer enters the ZVS state again.

The power supply voltage is input and then sequentially circulated, at the moment, the circuit splits the alternating voltage of 2 quadrants into high-frequency 4-quadrant pulse voltage, and the voltage waveform obtained on the primary side of the high-frequency transformer is shown in fig. 8.

Referring to fig. 9, the synchronous reduction circuit also uses an H-bridge connection mode of bidirectional electronic switches composed of IGBTs, but is different from the conventional switching mode, in which the conventional switching mode uses a conduction mode, and the synchronous reduction circuit uses an opposite turn-off mode, the IGBT switch groups K11, K12, K17, and K18 are one group of synchronous switches, and the IGBT switch groups K13, K14, K15, and K16 are another group of synchronous switches. The two groups of switches work alternately, and the four groups of switches of the synchronous reduction circuit are all in an on state under the condition that the high-frequency transformer has no energy.

When the secondary pulse voltage signal of the high-frequency transformer is positive, negative, and positive, the switches of the IGBT switch group K13, K14, K15, and K16 are turned off at the same time, and the current flows from the switches K11 and K12 to the switches K17 and K18, as shown in fig. 10 (a).

When the high-frequency transformer enters the ZVS state, K11, K12, K13, K14, K15, K16, K17 and K18 of the IGBT switch group are simultaneously conducted to enter zero-voltage switching, and a freewheeling circuit is provided for the LC filter channel, as shown in fig. 10 (b).

When the secondary output voltage of the high-frequency transformer is positive, negative and positive, the switches K11, K12, K17 and K18 of the IGBT switch group are turned off, and the switches K13, K14, K15 and K16 are kept on, so that the current flows from K16 to K15 to K14 and K13, and the voltage of the power supply commutation LC filter capacitor is still positive, negative and positive, as shown in fig. 10 (c).

When the high-frequency transformer enters a ZVS state, K11, K12, K13, K14, K15, K16, K17, and K18 of the IGBT switch group are simultaneously turned on to enter zero-voltage switching, and K11, K12, K13, and K14 of the IGBT switch group simultaneously provide a freewheeling circuit for the LC filtering channel, as shown in fig. 10 (d).

At this time, the 2-quadrant pulse voltage output from the high-frequency transformer is reduced to a 1-quadrant pulse voltage with the same width and different amplitude, and the voltage waveform on the inductor L2 is as shown in fig. 11.

When the power supply voltage is a negative half wave, and the secondary pulse voltage signal of the high-frequency transformer is negative positive and negative, the switches K13, K14, K15 and K16 of the IGBT switch group are turned off simultaneously, the current flows from the switches K17 and K18 to the switches K11 and K12, and the LC filter capacitor voltage is positive negative and positive, as shown in fig. 12 (a).

When the high-frequency transformer enters the ZVS state, K11, K12, K13, K14, K15, K16, K17 and K18 of the IGBT switch group are simultaneously conducted to enter zero-voltage switching, and a freewheeling circuit is provided for the LC filter channel, as shown in fig. 12 (b).

When the secondary output voltage of the high-frequency transformer is negative at the bottom and positive at the top, the IGBT switch groups K11, K12, K17 and K18 are turned off, and at the same time, the IGBT switch groups K13, K14, K15 and K16 are kept on, and the current flows from the switch K13 and the switch K14 to the switch K15 and the switch K16, so that the power supply commutation LC filter capacitor voltage is still positive at the top and negative at the bottom, as shown in fig. 12 (c).

When the high-frequency transformer enters a ZVS state, K11, K12, K13, K14, K15, K16, K17, and K18 of the IGBT switch group are simultaneously turned on to enter zero-voltage switching, and K11, K12, K13, and K14 of the IGBT switch group simultaneously provide a freewheeling circuit for the LC filtering channel, as shown in fig. 12 (d).

At this time, the 4-quadrant pulse voltage output by the high-frequency transformer is reduced to 2-quadrant pulse voltage with the same width and different amplitude, and the voltage waveform on the inductor L2 is as shown in fig. 13. The output ac pulse voltage passes through the low-channel LC filter to obtain a sine wave voltage, as shown in fig. 14.

Specifically, the synchronous fundamental wave circuit includes undervoltage unit, voltage division unit, input signal modulation unit and synchronous square wave modulation unit, the undervoltage unit is used for inserting direct current or alternating current power supply, the voltage of undervoltage unit's output passes through after the voltage division unit divides the voltage input extremely in the input signal modulation unit, the input signal modulation unit to synchronous square wave modulation unit output high-low level signal, synchronous square wave modulation unit according to the high-low level signal output of input signal modulation unit square wave signal output.

Further, the input signal modulation unit includes a positive half-cycle modulator and a negative half-cycle modulator, an input end of the positive half-cycle modulator is electrically connected to one end of the voltage division unit and one end of the power input end, an output end of the positive half-cycle modulator is electrically connected to one input end of the synchronous square wave modulation unit, an input end of the negative half-cycle modulator is electrically connected to the other end of the voltage division unit and the other end of the power input end, and an output end of the negative half-cycle modulator is electrically connected to the other input end of the synchronous square wave modulation unit.

It should be noted that the synchronous square wave modulation unit includes a positive half-cycle optocoupler switch module, a negative half-cycle optocoupler switch module, and an interlocking branch, the positive half-cycle optocoupler switch module outputs a positive half-cycle square wave signal according to the level signal of the input signal modulation unit, the negative half-cycle optocoupler switch module outputs a negative half-cycle square wave signal according to the level signal of the input signal modulation unit, and the interlocking branch is electrically connected with the output ends of the positive half-cycle optocoupler switch module and the negative half-cycle optocoupler switch module, respectively.

When in work: referring to fig. 15, when the commercial power is input from the input end of the synchronization signal J23 and then passes through the resistor R295, the chip U24 is fed into the under-voltage power supply circuit, when the voltage is lower than 120V, the optical coupler U25 does not work, the switch tube of the U22 is turned off, when the voltage is higher than 120V, the U22 is turned on, then the +5V-S power supply flows to +5V-F to supply power to the synchronization circuit, the resistor R292 and the resistor R299 form a voltage division circuit, the divided voltage is output to the U28 comparator as the comparison voltage, + BJ voltage is 0.45V, when the voltage is positive half cycle, L is greater than N, and when the + VL is greater than 0.45V, the U28A comparator sends a high level to the triode Q99, the optical coupler U29 works, and at this time, the positive half cycle voltage signal generates a square wave signal and is output through the triode Q96.

When N is greater than L when the voltage is negative half cycle, where + VL is less than + BJ, U28A is off than the machine. And the + VN is greater than + BJ, the U28B comparator works, the triode Q100 is conducted, and the optocoupler U31 provides a signal triode Q97 to work and input a negative half-cycle square wave signal. The resistor R45, the resistor R46, the triode Q25, the triode Q26, the resistor R64, the resistor R47, the triode Q27, the triode Q28 and the resistor R65 form an interlocking circuit, only one group of positive and negative synchronous square wave signals can work at the same time, and the situation that a rear driving circuit is switched on at the same time is avoided. The drive waveforms are shown in fig. 16(a), 16(b), and 16 (c).

Specifically, the synchronous carrier circuit includes a preceding-stage positive half-cycle carrier modulation unit and a preceding-stage negative half-cycle carrier modulation unit, the preceding-stage positive half-cycle fundamental wave modulation unit inputs the positive half-cycle carrier signal after conversion to the signal driving module according to the control signal of the driving control circuit and the square wave signal of the synchronous fundamental wave circuit, and the preceding-stage negative half-cycle carrier modulation unit inputs the positive half-cycle carrier signal after conversion to the signal driving module according to the control signal of the driving control circuit and the square wave signal of the synchronous fundamental wave circuit.

When in work: referring to fig. 17 and 18, when the input power voltage is positive half cycle, the + PWM supplies fundamental wave driving signals to N2, N4, N6 and N8, the frequency of the fundamental wave driving signals is the same as the frequency of the input power, and the + PWM supplies fundamental wave driving signals to gates U5A, U5B, U5C and U5D, PWMA, PWMB, PWMC and PWMD are high frequency phase shift signals, and after the + PWM supplies fundamental wave signals to gates U5A, U5B, U5C and U5D, the fundamental waves are converted into carrier wave PWMA, PWMB, PWMC and PWMD phase shift signals, and then converted into transistor Q1, transistor Q5, modulated transistor Q7, transistor Q13, transistor Q11, transistor Q19, transistor Q14 and transistor Q21, and outputs the converted fundamental wave driving signals to N1, N3, N5 and N7. In this case, N2, N4, N6, and N8 are fundamental waves, and N1, N3, N5, and N7 are modulated carriers.

The capacitor C50, the capacitor C54, the capacitor C59, and the capacitor C58 are rising edge delay capacitors, and the diode D71, the diode D89, the diode D78, and the diode D94 are falling edge fast discharge diodes.

Referring to fig. 19 and 20, when the input power voltage is negative half cycle, PWM provides fundamental wave driving signals to N1, N3, N5 and N7, and the frequency is the same as the input power frequency, and at the same time, PWM provides fundamental wave driving signals to gates U6A, U6B, U6C and U6D, PWMA, PWMB, PWMC and PWMD are high frequency phase shift signals, PWM provides fundamental wave signals to gates U6A, U6B, U6C and U6D, and the fundamental waves are converted into carrier waves PWMA, PWMB, PWMC and PWMD phase shift signals, and then are converted into transistors Q6, Q9, Q8, Q16, Q12, Q20, Q15 and Q22 outputs to N2, N4, N6 and N8. In this case, N1, N3, N5, and N7 are fundamental waves, and N2, N4, N6, and N8 are modulated carriers.

Referring to fig. 21, the working principle of phase shift driving is: a full-bridge phase-shifting chip of ATI company is used as a main control chip, an RC oscillating circuit consisting of a capacitor C48 and a resistor R303 provides a clock for the main control chip, a resistor R290 is a manual phase-shifting angle control potentiometer, PULSE _ W is a voltage stabilizing and waveform adjusting input end to control output voltage and waveform distortion, a capacitor C46 is a soft start capacitor, DISB is a DSP start control pin, and PWMA, PWMB, PWMC and PWMD are phase-shifting signal outputs. Also, referring to the driving waveforms, as shown in fig. 22:

specifically, the synchronous reduction circuit comprises a positive half-cycle driving branch and a negative half-cycle driving branch, wherein the input end of the positive half-cycle driving branch is electrically connected with two phase-shift signal output ends of the phase-shift driving module, the output end of the positive half-cycle driving branch inputs a reduced positive signal to the signal driving module, the input end of the negative half-cycle driving branch is electrically connected with the other two phase-shift signal output ends of the phase-shift driving module, and the output end of the negative half-cycle driving branch inputs a reduced negative signal to the signal driving module.

Referring to fig. 23, in the positive half-cycle mode, when the transformer secondary power is positive, the leading arms of PWMA and PWMD are turned on, the gate circuit U4A turns off the output, the a + turn-off output signals H1, H2, H7, and H8 turn off the output, the current is output from U4B via H3, H4, H5, and H6, and the output of the restoring circuit is positive,

in the positive half cycle mode, when the leading arm of the transformer secondary power supply is closed at the lower timing PWMA and PWMD, the gate circuit U4A is conducted to output, A + conduction output signals H1, H2, H7 and H8 are conducted to output, current is output from U4A through H1, H2, H7 and H8, H3, H4, H5 and H6 are closed to output, and then the output of the reduction circuit is still a positive signal.

In the negative half-cycle mode, when the secondary power supply of the transformer is negative and up, the leading arm of the PWMA and the PWMD is conducted, the gate circuit U4A is closed to output, A + closing output signals H1, H2, H7 and H8 are closed to output, current is output from U4B through H3, H4, H5 and H6, the output of the reduction circuit is a negative signal,

in the positive half-cycle mode, when the secondary power supply of the transformer is in a negative state, the overfront arms of PWMA and PWMD are closed, the gate circuit U4A is conducted and output, A + conduction output signals H1, H2, H7 and H8 are conducted and output, current is output from U4A through H1, H2, H7 and H8, H3, H4, H5 and H6 are closed and output, and then the output of the reduction circuit is still a negative signal. Please refer to the waveform diagram, as shown in fig. 24. The signal PWM SIGNAL is on at the front stage and off at the rear stage reduction stage PWM SIGNAL.

Referring to fig. 25, 26 and 27, the PWM control module is responsible for coordinating various aspects, and the content thereof includes a blower, a relay, temperature, smoke sensing, measurement and collection, AD/DA, DI/DO alarm communication, and the like. And the internal data of the machine is sent to the DTU after being collected and sent to the big data platform, meanwhile, the PWM control module collects the waveform distortion degree, performs data analysis on a power supply distortion point, and adjusts a phase shift angle in real time to correct the waveform.

The above embodiments are only used to illustrate the technical solutions of the present application, and not to limit the same; although the present application has been described in detail with reference to the foregoing embodiments, it should be understood by those of ordinary skill in the art that: the technical solutions described in the foregoing embodiments may still be modified, or some technical features may be equivalently replaced; and such modifications or substitutions do not depart from the spirit and scope of the corresponding technical solutions in the embodiments of the present application.

Claims

1. A full-voltage high-frequency direct conversion isolated safety power supply is characterized by comprising:

the driving device comprises a signal driving module and a driving control circuit, wherein the driving control end of the signal driving module is respectively and electrically connected with the front stage IGBT switch group, the high-frequency transformer and the rear stage IGBT switch group, and the signal driving module is electrically connected with the driving control circuit; and

synchronous signal generating device, synchronous signal generating device includes synchronous fundamental wave circuit, synchronous carrier circuit and synchronous reduction circuit, the input of synchronous fundamental wave circuit is used for inputing direct current or alternating current power supply, synchronous fundamental wave circuit's output respectively with signal drive module with synchronous carrier circuit electricity is connected, synchronous carrier circuit basis drive control circuit's control signal with synchronous fundamental wave circuit's square wave signal to signal drive module input transform's carrier signal, synchronous reduction circuit basis drive control circuit's control signal to signal drive module input reduction's signal.

2. The full-voltage high-frequency direct conversion isolated safety power supply according to claim 1, wherein the driving control circuit comprises a phase-shifting driving module and a PWM control module, the phase-shifting driving module is electrically connected to the synchronous fundamental wave circuit, the synchronous carrier circuit and the synchronous restoring circuit, respectively, and the PWM control module is electrically connected to the phase-shifting driving module.

3. The full-voltage high-frequency direct-conversion isolated safety power supply according to claim 2, further comprising a front stage LC filter and a rear stage LC filter, wherein the front stage LC filter is connected with the input end of the front stage IGBT switch group, and the rear stage LC filter is connected with the output end of the rear stage IGBT switch group.

4. A full-voltage high-frequency direct conversion isolated safety power supply according to any one of claims 1 to 3, wherein the synchronous fundamental wave circuit includes an undervoltage unit, a voltage dividing unit, an input signal modulation unit, and a synchronous square wave modulation unit, the undervoltage unit is configured to access a DC or AC power supply, a voltage at an output end of the undervoltage unit is divided by the voltage dividing unit and then input to the input signal modulation unit, the input signal modulation unit outputs high and low level signals to the synchronous square wave modulation unit, and the synchronous square wave modulation unit outputs a square wave signal according to the high and low level signals output by the input signal modulation unit.

5. The full-voltage high-frequency direct-conversion isolated safety power supply according to claim 4, wherein the input signal modulation unit comprises a positive half-cycle modulator and a negative half-cycle modulator, an input end of the positive half-cycle modulator is electrically connected to one end of the voltage dividing unit and one end of the power input end of the power supply, an output end of the positive half-cycle modulator is electrically connected to one input end of the synchronous square wave modulation unit, an input end of the negative half-cycle modulator is electrically connected to the other end of the voltage dividing unit and the other end of the power input end of the power supply, and an output end of the negative half-cycle modulator is electrically connected to the other input end of the synchronous square wave modulation unit.

6. The full-voltage high-frequency direct-conversion isolated safety power supply according to claim 4, wherein the synchronous square wave modulation unit comprises a positive half-cycle optical coupling switch module, a negative half-cycle optical coupling switch module and an interlocking branch, the positive half-cycle optical coupling switch module outputs a positive half-cycle square wave signal according to the level signal of the input signal modulation unit, the negative half-cycle optical coupling switch module outputs a negative half-cycle square wave signal according to the level signal of the input signal modulation unit, and the interlocking branch is electrically connected with the output ends of the positive half-cycle optical coupling switch module and the negative half-cycle optical coupling switch module respectively.

7. The full-voltage high-frequency direct-conversion isolated safety power supply according to claim 1, wherein the synchronous carrier circuit comprises a preceding positive half-cycle carrier modulation unit and a preceding negative half-cycle carrier modulation unit, the preceding positive half-cycle fundamental wave modulation unit inputs the converted positive half-cycle carrier signal to the signal driving module according to the control signal of the driving control circuit and the square wave signal of the synchronous fundamental wave circuit, and the preceding negative half-cycle carrier modulation unit inputs the converted positive half-cycle carrier signal to the signal driving module according to the control signal of the driving control circuit and the square wave signal of the synchronous fundamental wave circuit.

8. The full-voltage high-frequency direct conversion isolated safety power supply according to claim 2, wherein the synchronous reduction circuit comprises a positive half-cycle driving branch and a negative half-cycle driving branch, an input end of the positive half-cycle driving branch is electrically connected with two phase-shifted signal output ends of the phase-shifted driving module, an output end of the positive half-cycle driving branch inputs a reduced positive signal to the signal driving module, an input end of the negative half-cycle driving branch is electrically connected with the other two phase-shifted signal output ends of the phase-shifted driving module, and an output end of the negative half-cycle driving branch inputs a reduced negative signal to the signal driving module.

9. The full-voltage high-frequency direct-conversion isolated safety power supply according to claim 1, further comprising an input relay and an output relay, wherein the input relay is configured to be connected between a power input end and the front stage IGBT switch group, and the output relay is configured to be connected between a power output end and the rear stage IGBT switch group.

10. The full-voltage high-frequency direct-conversion isolated safety power supply according to claim 9, further comprising an input voltage detector, an output voltage detector, a temperature detector, and a wireless transmission module, wherein an input end of the input voltage detector is electrically connected to an output end of the input relay, an input end of the output voltage detector is electrically connected to an input end of the output relay, a detection end of the temperature detector is electrically connected to the front stage IGBT switch group, the high-frequency transformer, and the rear stage IGBT switch group, respectively, and the driving control circuit is electrically connected to the input voltage detector, the output voltage detector, an output end of the temperature detector, and the wireless transmission module, respectively.